\begin{tikzpicture}

\definecolor{darkgray176}{RGB}{176,176,176}
\definecolor{green}{RGB}{0,128,0}

\begin{groupplot}[group style={group size=1 by 2}]
\nextgroupplot[
tick align=outside,
tick pos=left,
title={A tale of 2 subplots},
x grid style={darkgray176},
xmajorgrids,
xmin=-0.245, xmax=5.145,
xtick style={color=black},
y grid style={darkgray176},
ylabel={Damped oscillation},
ymajorgrids,
ymin=-0.68685719, ymax=1.0803265,
ytick style={color=black}
]
\addplot [semithick, blue, mark=*, mark size=3, mark options={solid,fill=green}, only marks]
table {%
0 1
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0.8 0.13885029
1.2 0.09307413
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3.6 -0.022105356
4 0.018315639
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};
\addplot [semithick, black, dashed]
table {%
0 1
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0.2 0.25300172
0.3 -0.22892542
0.4 -0.54230031
0.5 -0.60653066
0.6 -0.44399794
0.7 -0.1534533
0.8 0.13885029
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1 0.36787944
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1.4 -0.19950113
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1.8 0.051080166
1.9 0.12100355
2 0.13533528
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2.2 0.034240059
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2.4 -0.073392366
2.5 -0.082084999
2.6 -0.060088587
2.7 -0.020767646
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2.9 0.04451472
3 0.049787068
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3.2 0.012596214
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3.4 -0.026999543
3.5 -0.030197383
3.6 -0.022105356
3.7 -0.0076399898
3.8 0.0069129487
3.9 0.01637605
4 0.018315639
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4.2 0.0046338881
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4.5 -0.011108997
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tick align=outside,
tick pos=left,
x grid style={darkgray176},
xlabel={time (s)},
xmajorgrids,
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xtick style={color=black},
y grid style={darkgray176},
ylabel={Undamped},
ymajorgrids,
ymin=-1.1, ymax=1.1,
ytick style={color=black}
]
\addplot [semithick, red, mark=*, mark size=3, mark options={solid}, only marks]
table {%
0 1
0.1 0.80901699
0.2 0.30901699
0.3 -0.30901699
0.4 -0.80901699
0.5 -1
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1 1
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1.2 0.30901699
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1.5 -1
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  anchor=north,
  text=black,
  rotate=0.0
]{\bfseries PLOT TITLE};
\end{tikzpicture}
